W. Sauer Orgelbau Frankfurt (Oder) is a German organ building workshop founded in 1857 by Wilhelm Sauer. In 1917, it came under the ownership of Walcker from Ludwigsburg, but retained its independence under its workshop manager Karl Ruther, including its name. It was one of the largest organ builders in Germany in the 19th and first half of the 20th centuries. After German reunification, in 1996, it was transformed into a GmbH with its headquarters and workshop in Müllrose (Brandenburg), and in 2000, a new founding took place. The company exists to this day.

The company developed into the leading organ builder in Prussia in the second half of the 19th century. Wilhelm Sauer retired in 1910 and sold his business to Paul Walcker, who had been the workshop manager since 1892 and deputy managing director since 1894. His nephew Oscar Walcker (1869–1948) from Ludwigsburg took over the company in 1917, which thereafter operated under the name "Wilhelm Sauer (Owner: Oscar Walcker)." Before World War II, between 100 and 120 employees were employed. Towards the end of the war, which had largely destroyed the workshops, they were plundered and used as a delousing facility. Anton Spallek embarked on a new beginning. By the end of 1945, six employees were working, and by the 1960s, there were around 30 employees. Gerhard Spallek, Anton Spallek's son, who had joined his father's workshop as an apprentice in 1945 and passed the master craftsman examination as an organ builder in 1962, took over the management in 1966.

In 1972, nationalization followed as "VEB Frankfurter Orgelbau Sauer," with 40 employees, and Gerhard Spallek became the factory director. On September 7, 1990, reprivatization took place as "W. Sauer Orgelbau (Owner: Werner Walcker-Mayer)." Gerhard Spallek served as managing director. In 1994, new workshops were established in Müllrose. From 1996, the company operated under "W. Sauer Orgelbau (Frankfurt/Oder) Dr. Walcker-Mayer GmbH & Co. KG." With the insolvency of the Walcker parent company in Kleinblittersdorf in 1999, Werner Walcker-Mayer withdrew as owner and managing director of W. Sauer Orgelbau. The profitable Müllrose company was to be included in the bankruptcy estate. The insolvency administrator awarded the contract for the new founding of the company, which operated profitably and was registered in the commercial register in June of the same year, to four committed men who contributed significant equity and took risks. Since January 27, 2000, it has operated under the name "W. Sauer Orgelbau Frankfurt (Oder) GmbH" and has been managed by these four shareholders ever since.

Wilhelm Sauer created organs in the late Romantic style and used cone chests. Instruments were produced in large numbers, but solid materials were usually valued. By 1910, 1,100 organs had been built. Sauer alone built 70 organs in Berlin. Under Paul Walcker, who switched to the slider chest, 90 organs were built in seven years. The number of new organ constructions under Oscar Walcker increased to about 1,600 by the time of World War II. Prior to nationalization, the company largely returned to the production of mechanical slider chests. After 1972, exports to Eastern European countries increased significantly. Opus 2276 was completed in 2011.

Most Sauer organs were inspired by French organ building, and Wilhelm Sauer apprenticed with none other than Aristide Cavaillé-Coll. Later, Sauer departed from the French design esthetic and developed a specific German romantic style. He held many patents for technical innovations in organ building. He often used cone chests and pneumatic action, which he brought to technical perfection. He used box-bellows (Kastenbälge) to achieve very stable wind pressure. Sauer organs were praised for their use of excellent materials and their perfect technical layout, efficient key and stop action, fine voicing, wide palette of tone colors, and perfect blending of stops. Stop combinations always sound homogeneous. Sauer developed his own, specific style of specifications and kept it for over 50 years, a period in which he built more than 1000 instruments. Among the most notable features, one can name:

Principals: the principal pipes placed in the organ's prospect suffered the greatest losses in most instruments as in many German organs the prospect pipes were confiscated in 1917 for war purposes, even if they were part of heritage monuments. Sauer mostly followed the ideas of Töpfer-Allihn in matters of scaling.

Mixtures and aliquots: Sauer preferred the Rauschquinte 2fach (2 2/3' and 2'), Cornett 3-5fach, Mixtur 2-4fach, and Progressio 4-5fach, not the high-pitched Scharff 5f and Cymbel 3fach.

Flutes and stopped flutes: Sauer put much effort into perfecting overblowing/ harmonic flutes – in this, indeed, he was a true follower of Cavaillé-Coll. In Chemnitz, there are 7 overblowing flutes: Flute (harmonique) 8' and Doppelflöte 8 (overblowing from c2) on the 1st manual, the Traversflöte 4', Konzertflöte 8' and Piccolo 2' on the second manual, Soloflöte and Fernflöte on the 3rd manual. Another frequently-used stop by Sauer is the Rohrflöte. Similar to the Rohrflöte is the Flauto dolce 4', which is not too weak and speaks clearly.

Conical shaped pipes: Sauer continued to build stops that were no longer popular in the end of the 19th century: Gemshorn, Spitzflöte, Quintatön. But he also employed new inventions such as Dulciana and Schalmei. The Schalmei was created by Sauer to imitate a reed stop. The pipes are shaped reversely conical and have a harmonic bridge and „Kernstiche". This stop is preserved only in a few of the remaining Sauer organs (such as Chemnitz!).

Strings: Gambe, Aeoline and Voix Celeste are the most common strings, the latter two often share the scales and are located near each other on the chest. When an Aeoline was absent, Sauer usually combined the Voix C. with the Salicional. The Fugara 4' is mostly located in the 2nd manual, where it replaces the Octave 4'. In the pedal, the Violon 16' is very narrowly scaled and sounds quite soft in contrast to the Kontrabaß 16'.

Reeds: In contrast to the trend of the time for free reeds (with their German protagonist Schulze), Sauer stood in the French tradition of Cavaillé-Coll with conventional reeds, although he built few free reed stops such as the Clarinette. However, the Clarinette in Chemnitz is manufactured as a striking reed, not a free reed. Sauer often was criticized for being „Frenchist" („Französelei") and therefore could not achieve commissions in Berlin for a long time! But, to put it more positively, he often was also called the German Cavaillé-Coll.

https://www.sauerorgelbau.de/
https://de.wikipedia.org/wiki/W._Sauer_Orgelbau_Frankfurt_(Oder)